Preparation of alkyl sulfonates



April 18, 1950 HARMAN 2,504,411

PREPARATION OF ALKYL SULFONATES Filed March 19, 1948 2 Sheets-Sheet 2 Effeci' of Merhanol Concerfl'rafion Temperature 15 Time 1.0 hrs. l- Odene 0.40 mole BisuH-H'e o. 43 rno\e(as 5M eoln.) Peroxide o.oo'l68 mole Methanol cc lnvenror Denharn Harman bq His A+forneq: i%@j2ff Patented 18, 1950' 'z,so4,411 I umrso s'mrss v PATENT OFFICE 2,504,411

PREPARATION OF ALKYL SULFONA'I'ES Denham Harman, Berkeley, Calif assignor to Shell Development Company, San Francisco,

CaliL,

a corporation of Delaware Application ms 1a, 1948, Serial No. mass 5 Claims. (01. zoo-sis) ,particularly the invention provides an improvement in such processes whereby the reaction is initiated by a class of compounds which tend to selectively promote the desired reaction in the absence of the undesirable side reactions heretofore thought to be unavoidable in the addition of bisulflte ions to oleflns. v V

The reaction between bisuiflte ions in aqueous solutions and water soluble compounds containing oleflnic double bonds has been known for many years. It was soon learned that .the reaction could be extended to water insoluble unsat- "rated compounds (with diminished yields) by the employment of a polar organic solvent. Initially the reaction was catalyzed by gaseous oxygen, but later investigators found that the reaction could be initiated by a variety of oxidizing agents. Kharasch, May and Mayo, Jr. Org. Chem. 3 175-192 (1938) reported that oxidizing agents such as nitrate or nitrite ions could be substituted for oxygen as the reaction initiator. U. 8. Patent 2,318,036 disclosed that still other oxidizing agents particularly those acting through the release of nascent oxygen including certain peroxides could be employed. While it was known that the reaction involved a free radical mechanism it was thought that compounds capable of oxidizing bisulflde were necessary to bring about the reaction. However, in addition to oxidizing the bisuiflte ions in the sense that an electron or a hydrogen atom is removed to convert the ions to a free radical thus oxidizing it from a charge of minus one to zero, such reagents also to a large extent convert the bisuiflte ions to sulfate ions. The conversion of bisuiflte to sulfate is, of course, a loss of reactant and it heretofore required the employment of large excesses of bisuiflte as well as initiator to obtain appreciable yields of alkyl sulfonates.

It is a principal object of the present invention to provide animproved method of forming organic sulfonates by the reaction of oleflnic compounds with bisuiflte ions in which method high yields are obtained in relatively short reaction times at moderate reaction temperatures without the necessary employment of large excesses of bisuiflte or initiator. A further object is the provision of a method of initiating the addition of bisuiflte ions to olefinic double bonds by the action of compounds which are relatively inert in respect to oxidizing bisuiflte ions to sulfate ions under the reaction conditions suitable for the addition of the bisulflde ions to an olefln. Another object is to provide a series of reaction initiators and organic mutual solvents which when employed together as reaction initiatormutual solvent pairs in a reaction between an olefin and a solution containing bisulfite ions -make possible the production of substantially quantitative yields of alkanesuli'onates. Still other objects and advantages will be apparent from the following discussion.

We have now discovered that the employment of certain organic peroxides. having the structure defined below, in the reaction process comprising the addition of bisuiflte ions to oleflnic compounds produces the following unobvious results. The defined class of peroxides initiate the addition reaction without oxidizing the bisuiflte ions to sulfate ions, therefore the employment of equivalent amounts of bisuiflte ions and minute amounts of the peroxides produce high yields in short times at moderate temperatures. The defined class of peroxides when employed in conjunction with certain organic mutual solvents in the form of reaction initiator-mutual solvent pairs, such as are illustrated below, provide a means of attaining substantially yields of the desired sulfonates under similar conditions of reaction time and temperature.

The reaction initiators suitable for the present process are organic peroxides in which the valences of the peroxy group 'OO- are satisfied by organic radicals at least one of which is connected to the peroxy group by a carbon atom bonded to three carbon atoms. Examples of individual peroxides suitable for the process include di-tertiary-butyl peroxide, 2,2-bis(tertiarybutylperoxy)butane, tertiary-butyl perbenzoate, tertiary-butyl tertiary-amyl peroxide. di-tertiary-amyl peroxide, 2,2-bis(tertiary-amylperoxy) butane, 2,2 bis(tertiary butylperoxy) propane, 2-tertiary-butylperoxy-2-methylhexane, tertiary-amyl perbenzoate, tertiary-butyl perlaurate, tertiary-butyl peracetate.

The tertiary-alkyl peresters in general and tertiary-alkyl perbenzoates in particular form a preferred class of reaction initiators providing extremely high yields of alkyl sulfonates when employed in conjunction with a variety of particular organic solvents. Examples of the tertiary-alkyl peresters include, tertiary-butyl perbenzoate, tertiary-amyl perbenzoate, 2-benzoylperoxy-1,1- dimethylhexane, tertiary-amyl perlaurate, tertiary-butyl perlaurate.

The 2,2-bis(tertiary-alkylperoxy) alkanes form another preferred class of reaction initiators for as mutual solvents with the reaction initiators of the defined structure result in surprisingly improved yields of alkane sulfonates comprise polar organic solvents of the group consisting of primary alcohols of less than 4 carbon atoms,

cyclic diethers, and organic amines. Examples of suitable organic mutual solvents include. methyl alcohol, ethyl alcohol, dioxane, diethylamine, hexanolamine, pyridine, 'propyl alcohol, isopropyl alcohol, ortho, meta or para-toluidine, N-methylaniline, pentanolamine, aniline, N,Ndimethylaniline, butylamine, methyldioxaue, symstandardized conditions chosen to illustrate by comparison the importance of the various solvent-peroxide relationships, examples illustrating the preferred modes of conducting the present process are presented below.

The present improved process is in general applicable to the same classes of unsaturated compounds that have :been found in the past to be suitable reactants for the addition of bisulflte ions. In the past, the addition reaction, even where a l-olefin was employed, generally produced yields of 12% or less unless very long reaction periods and large excesses of bisulflte (along with a corresponding excess of reaction initiator) were employed when the olefin contained more than about 6 carbon atoms. The present invention adapts the addition reaction to economical conversions of unsaturated compounds of up to 19 or more carbon atoms. Examples of unsaturated compounds which may suitably be converted to organic sulfonates by the present process include alkenes such as the butenes, the hexenes, the octenes, the octadienes, the decenes, the dodecenes, the tetradecenes, and

5. tertiary-butyl perbenzoate with pyridine.

6. 2,2-bis(tertiary-butylperoxy)butane with pyridine.

7. di-tertiary-butyl peroxide with pyridine.

metrical-dimethyldioxane, N-methyl N -'ethylthe hexadecenes, cycloalkenes such as cyclohexaniline, propylamine, pentylamine, methylethylene, the ethylcyclohexenes, the cyclohexadienes, amine, dipropylamine, 2, 3 @r 4-methylpyridine, the pentyl cyclopentenes, the dibutylcyclohexpentanolamine, heptanolamine, N-methyl-paraenes, the ethyldibutylcyclohexenes, and the detoluidine,N-ethylaniline. cyclohexenes, the alkenylaryl hydrocarbons such An interesting relation between the peroxide 1: as styrene, the polybutenylbenzenes, the butenyland the polar organic mutual solvent has been benzenes, the hexenylbenzenes and the decenylobserved to make possible substantially quanbenzenes. In general, suitable starting comtitative conversion of the olefin to alkanesulfonpounds for the present improved process comate when certain of the peroxides are employed prise unsaturated compounds or not more than in conjunction with certain of the solvents. The about 20 carbon atoms which contain at least following table illustrating reactions conducted one oleflnic double bond. Where the production under essentially the same conditions is preof substantially pure organic sulfonates is desented to show this relationship. The reactions sired mono-olefinic hydrocarbons are preferred, were conducted by heating a mixture composed particularly the alkenes, and particularly the of 1octene (0.4 mole), ammonium bisulflte (0.43 0 l-oleflns containing 4 to 20 carbon atoms. mole as a 5M solution), peroxide 1.6 mls. and Any of the sources of bisulfite ions suitable for polar organic mutual solvent 80 mls. The yield the basic reaction process as heretofore accomof ammonium octanesulfonate obtained from plished may be employed in the present process. each peroxide and polar organic mutual' solvent In general any compound forming bisuliite ions combination is presented as to per cent by weight in an ionic media not in itself reactive with oleof l-octene converted to ammonium octanesulflnic double bonds may be used as the source fonate. of the bisulflte ions. The acid salts of sulfurous Dl-tert-butyl t-butylperbenzo l "1 be I T-l20 C Methanol 3. a ass as o Ethanol- 2o. 2 s4 P -59 69 74 o o o as Diethylamine.. 0 0 5 Dioxane 0 23 0 Acetone 0 (I) l Blank (water only) 0 0 0 0 1 This combination was not employed.

' A peroxide of the class heretofore employed.

The following particularly preferred reaction acid, the free acid in solution, or gaseous sulfur initiator-mutual solvent pairs have been found dioxide are examples of sources of bisulflte ions to provide surprisingly high yields of sulfonates. suitable for the present process.

. In the preparation of detergents, perhaps the g g zg butylpemxwbutane with most important commercial application of the 2. tertiary-butyl perbenzoate with methanol. organic summates the employment of aqueous solutions of the sodium or ammonium bisulflte 3. tertiary-butyl perbenzoate with hexanolamine. is particularly advantageous Ammonium bisub 4. tertiary-butyi perbenzoate with ethanol.

fite is particularly advantageous because ofv itsreactivity, its employment enables the substantially quantitative conversion of alkenes to ammonium alkanesulfonates. Sodium bisulilte, while in general less reactive and more diillcult As the above reactions were conducted under 75 to remove from the reaction products is advantageous in that the sodium alkanesulfonates 1 of bisulfite in: the aqueous phase of the improved process isillustrated bythe following. Three additionreactions were conducted employing the same reaction initiator, the same aikene, the same polar organic mutual solvent in the same concentrations, and the same volumes of aqueous ammonium bisulfite in which the concentration of the bisulfite was varied. Each of the reaction mixtures were heated to a temperature of 120 C. for 16 hours with constant agitation.

'The conversion of the ammonium bisulflte to ammonium alkanesulfonate was measured by the olefin consumption.

Initial concentra- Per cent of 'tion of smmoniammonium um bisulilte, bisuliite remoles/liter acted 8 mum: is tertiary-butyl perbenloate is mm 00' c. to 120' c.

As mentioned previously, the characteristics of the particular organic mutual solvent employed with the various reaction initiators causes considerable variation in the yield of sulfonate obtained. The eflects of variations in the amount of the organic solvent in the amounts of ammonium octanesulfonate produced by agitating a reaction mixture composed of 0.4 moles of l-octene, 0.43 mole of ammonium bisulflte as a 5M.solution and 1.6 mls. of tertiary-butyl perbenzoate for two hours at 75 c. in the presence of various amounts of methanol are illustrated by Figure 2. In general, the organic mutual solvent may suitably be employed in volume ratios with the olefin of from 1 volume olefin to from 0.75 to v 1.50 volumes of solvent, but is preferably employed in ratios of olefin to solvent of 1.to from 0.9 to 1.2.

The amount of reaction initiator required in the improved process is very small, in general from 0.001 to 0.1 mole of the liquid peroxide per mole of the olefin are sufficient and while more may suitably be employed such employment results in but little increase in yield of sulfonate. The preferred concentration of reaction initiator is a mole ratio of from 0.005 to 0.05 mole of initiator per mole of olefinic compound. The effect of varying the amount of reaction initiator is illustrated by the following examples. Reaction mixtures comprising 0.4 mole l-octene, 0. 13 mole of ammonium bisulfite as a 5M aqueous solution, 80 moles of methanol, and the following amounts of tertiary-butyl perbenzoate were agitated for 2 hours at 75 C. and the per cent conversion of l-octene to ammonium octyl sulfonate determined.

Amount peroxide employed p m; Moles of sulfonate formed Conversion Moles of peroxide employed moles per liter and it is preferable to employ substantially equimolar portions of bisulflte to olefin. However, wherever it is desirable, either the bisulflte or the olefin may be employed in excess of the other.

A relatively wide range of temperatures may be used in the improved process. In general, temperatures from C. to 200 C. are suitable. In a the present process, in addition to its effect upon the olefln and the bisulflte reactants which is one of activating the molecules or ions thus increasing the rate of the desired reaction as well as any possible side reactions, temperaturematerially influences the rate of decomposition of the reaction initiaton. Where the temperature is increased substantially above the temperature at which the reaction initiator begins to dissociate into free radicals, the rate of its dissociation may become greater than the rate at which the radicals attack the bisulilte ions and excessive amounts of the reaction initiator will be consumed for the rate of reaction obtained. The ef- As mentioned above, the blsulfite addition reaction hadheretofore been conducted over relatively long periods of reaction to obtain suitable yields. An important feature of the improved process is the fact that high yields of alkyl sul- Ionates may be obtained within reaction periods of 3 or less hours as compared to 10 or more required'by the process as heretofore conducted. Where the length of the reaction period is critical; even higher yields per unit of time may be obtained by employing an excess of the reaction initiator.

The process may be conducted in a batchwise or continuous manner. below normal atmospheric pressure may be employed. However, the improved process is preferably conducted by maintaining the reactants in the liquid phase at an elevated temperature and it is therefore generally more convenient to employ pressures above normal atmosphere.

.The, following detailed examples illustrate the valuable results obtained by the resent improved process as applied to specific unsaturated compounds as well as a comparison between the reaction initiators of the invention with those heretofore employed. As many variations of reactants and reaction conditions are within the scope of the invention, the examples are illustrative only and the invention is not limited to Reactionpressures at or of ammonium octanesulfonate.

the particular materials or reaction conditions recited therein.

Example I-The addition of bisulfite ions to olefin: in the presence of an oxidizing agent butyl perbenzoate for 2 hours at a temperature of I 75 C. produced a 73% yield of ammonium dodecanesulfonate.

1 VII. Heating 0.2 mole of l-tetradecene with 0.2 mole of aqueous bisulfite in the form of a 5M am- For the purp ses of comparison. he following 5 monium bisulfite solution in the presence of a0 bisulfite addition reactions, a-d, are included to mls. of methanol and 0.00268 mole of tertiary. illustrate suchreactions as heretofore conducted butyl perbenzoate for 2 hours at a temperature of n h presence of gaseous y n in h form of 75 0. produced a 60% yield of ammonium tetraair as the reaction initiator. In each case l-oc- 1 e ulf use, tene and aqueous bisulfite ions in the former an VIII. Heating 0.2 mole of l-hexadecene with ammonium bisulfite solution containing 0.374 0.2 mole of aqueous bisulfite in the form oi. a 5M mole of bisulfite per 100 mls. were employed as the ammonium bisulfite solution in the presence of reactants in a molar ratio of olefin to bisulfite of 80 mls. of methanol and 0.00268 mole of tertiary- 1:0.86. The reactants were combined in the butyl perbenzoate for 2 hours at a temperature listed amounts by weight in a stainless steel reof 75 C. produced a 22% yield of ammonium actor having a volume of 300 mls. In each case hexadecanesulfonate. the reaction mixtures were agitated for22 hours Ix. The sodium salt of octanesulfonic acid was at a temperature of 120 C. The mixed reaction prepared by the procedure of Example II replacproducts were separated into aqueous and organic ing ammonium bisulfite by sodium bisulfite. liquid phases and an aliquot portion of the aque- I claim as my invention: ous phase evaporated to dryness and taken up in 1. In a process for the production of an aikaneisopropyl alcohol. Hydrogen chloride gas was sulfonate by the direct addition of a bisulfite ion bubbled into the alcohol solution and the precipito an olefin the improvement which comprises tate ammonium chloride filtered off. The aloo- 25 heating to a temperature of from 60 C. to 120 hol and hydrogen chloride were then removed by C. a mixture of a l-olefin 01 from 2 to 20 carbonvacuum distillation under pressures gradually reatoms, a substantially equlmola proportion 01 duced to 1 mm. at a temperature of 100 C. bisulfite ions in the form of an aqueous solution, From the weight of the alkanesulfonic acid oban amount of methanol forming a volume ratio tained the yield of sulfonates based on. the of olefin to alcohol 0! 1 to between 0.75 and 1.50, amount of l-octene employed was calculated. and an amount r uty p o y a. Go. P. 8.1.

o... 48.8 100 46.0 5.1 b 48.8 100 100 46.0 5.1 c... 48.8 100 100 48.8 0 a. 24.4 so 200 24.4 47 0 Only the air in the bomb at atmospheric pressure.

Examples II to lX-The improved process of preparing alkanesuljonates II. Heating 67.2 mls. of l-ootene and 87.2 mls. of a 5M solution of ammonium bisulfite to 120 C. for 2 hours in a closed vessel in the presence of 1.6 mls. of 2,2-bis(tertiary-butylperoxy)butane and 80 mls. of methanol produced a 96.8% yield 111. Heating 67.2 mls. of l-octene and 87.2 mls. of a 5M solution of ammonium bisulfite to 120 C. for 2 hours in a closed vessel in the presence of 1.6 mls. of tertiary-butyl perbenzoate and 80 mls. of methanol produced a 89% yield of ammonium octanesulfonate.

IV. Heating 67.2 mls. of 1-octene and 87.2 mls. of a 5M solution of ammonium bisulfite to 120 C. for 2 hours in a closed vessel in the presence of 1.6 mls. of tertiary-butyl perbenzoate and 80 mls. of'hexanolamine produced a 78% yield of ammonium octanesulfonate.

V. Heating 0.2 mole of l-decene with 0.2 mole of aqueous bisulfite in the form of a 5M ammonium bisulfite solution in the presence of 80 mls. of methanol and 0.00268 mole of tertiary-butyl perbenzoate for 2 hours at a temperature of C. produced a 77% yield of ammonium decanesulionate.

VI. Heating 0.2 mole of l-dodecene with 0.2 mole of aqueous bisulfite in the form of a 5M ammonium bisulfite solution in the presence of 80 mls. of methanol and 0.00268 mole of tertiarybutane forming a molar ratio of olefin to peroxide or between 1 to 0.001 and 1 to 0.10.

2. In a process for the production of an alkanesulfonate by the direct addition of a bisulfite ion to an olefin the improvement which comprises heating to a temperature of from 60 C. to C. a mixture of a i-olefin of from 2 to 20 carbon atoms, a substantially equimolar proportion of bisulfite ions in the form of an aqueous solution, an amount 01' methanol forming a volume ratio 01' olefin to alcohol of 1 to between 0.75 and 1.50, and an amount of tertiary-butyl perbenzoate forming a molar ratio of olefin to peroxide of between 1 to 0.001 and 1 to 0.10.

3. In a process for the production of an alkanesuli'onate by the direct addition of a bisulfite ion to an olefin the improvement which comprises heating to a temperature of from 60 C. to 120 C. a mixture oi a l-olefin of from 2 to 20 carbon atoms, a substantially equimolar proportion of bisulfite ions in the form of an aqueous solution, an amount of pyridine forming a. volume ratio of olefin to pyridene of 1 to between 0.75 and 1.50,

and an amount of di-tertiary-butyl peroxide forming a molar ratio of olefin to peroxideof between 1 to 0.001 and 1 to 0.10.

4. In a process for the production of an alkanesulfonate by the reaction of an olefin with a substantially equimolar proportion of bisulfite ions in aqueous solution, the improvement which comprises conducting the reaction at temperatures 7 between 60 C. and 120 C. in the presence of a a 9 reaction initiator-mutual solvent pair of the group consisting of,

2,2-bis(tertiary-butylperoxy)butane with methanol tertiary-butyl perbenzoate with methanol tertiary-butyl perbenzoate with hexanolamine tertiary-butyl perbenzoate with ethanol tertiary-butyl perbenzoate with pyridine- 2,2-'bis(tertiary-butylperoxy)butane with pyridine di-tertiary-butyl peroxide with pyridine comprises employing a reaction initiator-mutual solvent pair of the group consisting of, ZB-bisflartiaiy-butylperoxy) butane with methauol 10 tertiary-butyl Derbenzoate with methanol tertiary-butyl perbenzoate with hexanolamine tertiary-butyl perbenzoate with ethanol tertiary-butyl perbenzoate with pyridine 2,2-bis(tertiary-butylperoxy)butane with pyridine di-tertiary-butyl peroxide with pyridine.

i DENHAM HARMAN.

REFERENCES crrEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,268,443 Crowder Dec. 30, 1941' 2,318,036 Werntz L May 4, 1943 2,398,428 Hani'ord Apr. 18, 1946 OTHER REFERENCES Kharasch et al., J. Org. Chem..-V ol. 8, paces 175-192, 1938.

Mayo, Chemical Reviews, Vol. 27, pages 894- 399, 1940. i i V 

4. IN A PROCESS FOR THE PRODUCTION OF AN ALKANESULFONATE BY THE REACTION OF AN OLEFIN WITH A SUBSTANTIALLY EQUIMOLAR PROPORTION OF BISULFITE IONS IN AQUEOUS SOLUTION, THE IMPROVEMENT WHICH COMPRISES CONDUCTING THE REACTION AT TEMPERATURES BETWEEN 60*C. AND 120*C. IN THE PRESENCE OF A REACTION INITIATOR-MUTUAL SOLVENT PAIR OF THE GROUP CONSISTING OF, 